Brake and clutch operating means on looms



1962 A. F. CRAIG ETAL BRAKE AND CLUTCH OPERATING MEANS 0N LOOMS 4 Sheets-Sheet 1 Filed March 4, 1958 .Zrzz; (117)5016 (Ira/2L eff IJIIQL enzzalz/ Dec. 25, 1962 A. F. CRAIG ETAL BRAKE AND CLUTCH OPERATING MEANS ON LOOMS Filed March 4, 1958 4 Sheets-Sheet 2 7 CZZZIZEZZ/ .M.MCL

Dec. 25, 1962 A. F. CRAIG ETA]. 3,070,133

BRAKE AND CLUTCH OPERATING MEANS ON LOOMS Filed March 4, 1958 4 Sheets-Sheet 3 CUMP/Pfiffffl 14W? SW/ 1 1) .ZITLIJGILiZOIG 14.1 Craig Dec. 25, 1962 A, F. CRAIG ETAL I BRAKE AND CLUTCH OPERATING MEANS ON LOOMS 4 Sheets-Sheet 4 Filed March 4, 1958 U l was? l er 1 El f This invention has reference to looms and while it is particularly applicable to carpet looms the invention is not limited thereto.

It is known to provide carpet looms with a clutch through which the drive is transmitted to the moving parts of the loom and a brake by which the moving parts are quickly brought to rest when the clutch is released, means being provided whereby on starting the loom the bake is released and immediately thereafter the clutch is engaged and whereby on stopping the loom the clutch is released and immediately thereafter the brake applied. Further in such looms it is known to provide emergency stop means whereby in the event of the shuttle failing to enter either of the shuttle boxes provided at each side of the loom the aforesaid clutch is released and the brake applied to bring the loom to rest.

in order to protect the vital parts of the loom it is desirable that such emergency stop means should function as quickly as possible. The more quickly this is accomplished the less likelihood of the emergency stop motion imposing a limit on the speed at which the loom can be run. Thus the speed at which the emergency stop means function is a fee or which restricts the speed of the loom.

The present invention has therefore for its object to provide an improved driving, braking and emergency stop means for a loom which will give adequate protection to the moving parts of the loom in the event of an emergency without affecting the greatest design speed of the loom.

According to the present invention a loom is provided with a control system comprising a pneumatic clutch through which the drive to the loom is transmitted, a main valve set in the normally closed position controlling the admission and exhaust of compressed air to the clutch, a pneumatic brake which aids in bringing the loom to rest, a main valve set in the normally open position controlling the admission and exhaust of compressed air to the brake, a pilot solenoid operated valve controlling the p ssage of air pressure to operate the said main valves, manually controlled switches by which the energising circult of the solenoid can be closed to operate the pilot valve so that the compressed air is delivered thereby to operate the main valves whereby the clutch is engaged and the brake released and means whereby the energising circuit is interrupted if the shuttle fails to enter either of the shuttle boxes, the de-energising of the solenoid resulting in the pilot valve operating to return the main valves to their normal positions whereupon the clutch is released and the brake applied.

The invention further consists in a loom provided with a control system as set forth in the preceding paragraph wherein a control valve is introduced between the clutch and its main valve which control valve is such that it ensures a slow build-up of pressure in the clutch so that the clutch cannot engage before the brake is released.

Quick exhaust valves are fitted to the brake and clutch so tiat they operate immediately the pressure therein is reduced.

The invention will now be described with reference to the accompanying drawings which show only such parts Patented Dec. 2 9 1962 of a carpet loom as are necessary for a proper understanding of the invention wherein:

PEGURE l is an elevation, partly in section, of part of one end of a carpet loom, the lay-sword being omitted;

*TGURE 2 is an end view thereof to a smaller scale, this view showing the lay-sword but omitting the loom frame;

2a is an elevational view of the motor control box;

FIGURE 3 shows diagrammatically the driving, braking, emergency stop means therefor and also showing diagrammatically the electric circuit;

FIGURE 4 shows diagrammatically in perspective the mechanism by which the energising circuit is de-energised and shock absorbing means brought into operation in the event of a shuttle failing to enter a shuttle box.

in the drawings 23 designates the lay-sword of the loom, 2d designates the rocking shaft on which the laysword is secured, 25 designates the top reed case, 26 designates the reed, 27 designates one of the side supporting frames of the loom and 28 designates the take-up roller, all such parts being common to carpet looms of conventional construction.

The take-up roller is iournalled in end bearing 28a supported by the side frames as shown in FIGURE 1. This figure also shows the usual breast beam 27:: and also the horizontal breast plate 2%. The breast beam extends between the side frames and to the breast beam is secured a bracket 27c carrying the wire magazine guide 27a.

The improved carpet loom is provided with an electric driving motor 1 which drives a pinion wheel 2 through a pneumatic clutch 3. The pinion wheel 2 in turn drives a gear wheel 4 fast on the loom crankshaft 5 to which is fitted to pneumatic brake 6. The loom shaft 5 is shown journalled in a bearing 5a supported by a pedestal 5!). Air is introduced to the clutch and exhausted from the brake and vice versa through a clutch master valve 7 and brake master valve ll respectively operated by means of air under pressure supplied by a solenoid operated pilot valve 9, the solenoid designated 91:. Air is supplied to the valves 7, and F5 by the pipe lines 7a, 3a and 9a espectively and the air which operates the valves '7 and d is supplied thereto from the pilot valve 9 through pipe lines 7b and 3b respective.y. Air is supplied from valve 7 to the clutch through pipe line 7c and air is supplied to the brake from valve 8 through pipe line tic.

The master valve 7 for clutch operation is normally closed while the master valve 3 for the bralie operation is normally open.

The circuit of the solenoid 9b, indicated by the leads 90, includes manually operated start buttons Jt a any one of which, when depressed, closes said circuit to energise the solenoid 912. Further said circuit includes stopping buttons itl any one of which when depressed interrupts said circuit to de-energise the solenoid. The switches ill and liia are of the usual push-button on/oif type.

Also included in the circuit are two normally closed micro switches 11, one at each side of the loom, said switches being such that a slight depression of their contracts is sufficient to interrupt the circuit.

Each shuttle box, as is the usual practice, is provided with a swell lla which, in the event of the shuttle failing to enter a shuttle box, permits protector pawls 12 to be let down in the knOck-0ff position. The protector pawls are fast on a protector shaft 15 supported by the lay to travel therewith. When the lay 13 comes towards its beat-up position the said pawls attached to the lay mechanism are each engaged with the pawl face 14 of a boss 15 which is free to revo ve on a knock-off shaft 160 for a limited angle 6 only. Shafts 16c are supported in bearings in brackets 16d secured to the loom frame. This ac /ones limited angle is a measure of time and is the allowable time for the knock'oif boss to open a micro-switch ll to de-energise the solenoid. T he protector shaft lo is biased by means of tension springs 12:! each anchored at one end to the lay-sword and at its other end to a clamp 16c fast on said shaft, see 2. In the drawings only one of said springs is shown.

When the loom is at rest with motor 1 running free the solenoid is tie-energised and consequently the clutch master valve 7 is in the shut-off or normally closed position. The brake master valve 8 is in the normally open position, and therefore air pressure is applying the brake on the crankshaft.

When any of the loom start buttons llia are pressed the solenoid is energised so that the pilot air valve 9 operates to simultaneously close the brake master valve 8 and open the clutch master valve '1" thereby disengaging the brake and engaging the clutch. To avoid any possibility of overlapping-piz. engaging the clutch an instant before exhausting the brake, a speed control valve 17 is fitted in the air line just before the clutch, which permits a slow buildup of pressure in the clutch by restricting the flow of air therethrough. This does not impede the exhausting of the clutch due to the fact that quick exhaust valves l8 and 19 are fitted to clutch and rake respectively which valves operate when the compressed is being exhausted by the master valves to release part of the compressed air in the clutch and brake immediately the pressure is reduced.

When any of the stop buttons 16 is depressed the solenoid of the pilot valve is de-energised which simultaneously opens the brake master valve 8 and closes the clutch master valve '7 thereby freeing the clutch pinion 2 and applying the brake on the crankshaft. The driving motor is left running ready for a restart and is stopped, only when necessary, by the push-button on the motor control box in the event of the loom shuttle 21 failing to reach its position in either shuttle box, the protector pawls 12 are let down in the knock-oif position and when the lay comes towards its beat-up position the pawls attached to the lay mechanism are en aged with the pawl faces of the bosses 15 which are free to revolve on the knock-oil shaft Soc for a limited angle only. This limited angle is a measure of time, and is the allowable time for the knock-oil boss to operate a micro-switch ll which de-energises the solenoid which operates the pilot valve 9 which in turn closes clutch valve '7 and opens brake valve 8 thus bringing the loom to a stop. All this is accomplished in a fraction of a second after the microswitch is operated and before the loom is stopped by the action of the shock absorbing springs 22. The micro switch is operated by a pawl face 14a on the boss 15 which face co-operates with the lever 14b of the micro switch. it will be understood that the loom is provided with the usual shock absorbing means which function when the loom is being brought to rest due to an emergency stop and may be or any suitable construction. For example, the boss alter operating the micro switch, may co-operate with a boss 315a on the knock-oil shaft ice, the boss lfia carrying a lever 16!: connected to the shock absorbing spring 22. A suitable form of shock absorbing means is shown in British Patent No. 738,408. This knock-oil gear is fitted on both sides of the loom.

Each boss 15 is rotated by a pawl 12 against the action of a resetting tension spring l5a anchored at one end to an arm lSb fast on the boss and at its other end to a fixture 150 on the loom frame.

The electric circuit is shown in FIGURE 3 wherein it will be seen that the main leads are connected to the motor control panel 2 4 which contains a relay, not shown, which controls the energising of the solenoid 9b to which it is connected by leads 9d. From the control panel extend the leads 90 which form a circuit in which are included in series the normally closed stop button switches it the two microswitches l1. and tie left hand start button switches Fla. The other two start button switches are connected in parallel with the first start button switch. The start button switches are normally open. 5 The motor 7. is started by a start button switch in the control panel and when the motor is started the clutch is free.

The leads from the contractor panel to the motor are not shown.

in starting the loom, after the motor is running, a button switch is closed and this closes the circuit w ch includes the leads 9c. This reSults in the relay being energised to close the circuit containing the leads 9d and solenoid S b which latter then opens the normally closed air valve abovedescribed. In the event of a knocP-orl by the pawls ti micro-switches ll are opened to interrupt the circuit containing the relay which latter is thereby ale-energised so that the solenoid is likewise deenergised. The said valve then closes as explained. The circuit containing the solenoid may be interrupted by operating of the press button switches The said control panel and the press button switches are mounted on a channel beam ldb extending longitudinally of the loom and supported by brackets llllc secured to the loom frame.

The foregoing system provides a safe and quick meth- 0d of emergency sto ping and the almost instantaneous stop which follows the first movement of the protector mechanism is something not hitherto accomplished in heavy carpet looms.

In previous looms the mechanical method of emergency llnoclooir involving levers, rods and springs, required the maximum amount of time to free the clutch and apply the brake in that order. As time is a measurement of loom movement it wi l be obvious that the smaller the increment of time involved from the first movement of the knock-off gear to the freeing of the clutch and ap plying the brake, the greater will be the margin of safety on the vital moving parts of the loom. r 'iis in turn en- 40 ables the loom to be run faster while still giving adequate protection to its vital parts than is possible with looms having known forms of emergency stop mechanisms.

Further a pressure reducing valve 23 regulates the pressure of the air to clutch which can be manually set V to give pressure suitable for driving but low enough to permit of clutch slip in the event of an accidental overload.

Such control is completely interlocked electrically for hand turning, reversing, inching and re-starting after emergency stops and at the same time is simple and elf rtless to operate as the traditional starting handle which normally runs the full width or" loo-1n is replaced by electrical push buttons arranged at intervals across the loom front. it also makes the fitting of weft and warp stop motions-if they are requiredmore easily applied.

What we claim is:

1. A loom provided wi .1 a control system comprising a pneumatic clutch through which the drive to the loom is tran mitted, a pneumatically operated main valve controlling the admission and exhaust of compressed air to and from the clutch, the of the compressed air engaging the clutch and the exhaust of the air therefrom releasing the clutch, a pneumatic brake to aid in bringing the loom to rest, a second pneumatically operated main valve controlling the admission and exhaust of compressed air to and from the brake, the admission of the compressed air applying the brake and the exhaust of the air therefrom releasing the brake, a solenoid operated pilot valve controlling the passage of air pressure to operate said main valves, manually operable switches by which the energising circuit of the solenoid can be closed and interrupted to start and stop the loom, at least one normally closed micro-switch in said circuit, a protector shaft supported by the lay to travel therewith, pawls fast 75 on said shaft, knock-oil shafts and means to open the E's micro-switch comprising a boss on at least one of the knock-off shafts, said boss having a pawl face and being free to revolve on its shaft to a limited angle only, and means by which the pawl face is engaged by a pawl when the shuttle fails to enter a shuttle box so that the boss is rotated to open the micro-switch to interrupt the solenoid energising circuit and thereby deenergise the solenoid.

2. A loom provided with a control system as claimed in claim 1 wherein a control valve is introduced between the clutch and its main valve which control valve is such that it ensures a slow build-up of pressure in the clutch so that the clutch cannot engage before the brake is released.

3. A loom provided with a control system as claimed in claim 1 wherein quick exhaust valves are fitted to the brake and clutch so that they operate immediately the pressure therein is reduced.

References Cited in the file of this patent UNITED STATES PATENTS 2,193,068 Keck Mar. 12, 1940 2,472,452 Wissman June 7, 1949 2,600,667 Mason June 17, 1952 2,615,475 Eves Oct. 28, 1952 2,636,581 Bitler Apr. 28, 1953 2,794,523 Cortelli et al. June 4, 1957 2,805,686 Godschalx Sept. 10, 1957 2,838,149 Burton June 10', 1958 FOREIGN PATENTS 738,408 Great Britain Oct. 12, 1955 

